Home
Class 9
PHYSICS
Flash and thunder are produced simultane...

Flash and thunder are produced simultaneously. But thunder is heard a few seconds after the fash is seen. Why?

Text Solution

Verified by Experts

The speed of sound in air is 344 `ms^(-2)` while that of light is `3xx10^(8) ms^(-1)`. Thus the speed of light is much more than that of sound. So, the Nash is seen first and the sound of thunder is heard a little later.
Promotional Banner

Topper's Solved these Questions

  • SOUND

    KUMAR PRAKASHAN|Exercise QUESTIONS AND ANSWERS ( Give scientific reason for the following statements:)|5 Videos

  • SOUND

    KUMAR PRAKASHAN|Exercise QUESTIONS AND ANSWERS ( Match the following property :)|4 Videos

  • SOUND

    KUMAR PRAKASHAN|Exercise QUESTIONS AND ANSWERS (State whether the following statements are true or false:)|15 Videos

  • QUESTION PAPER 03

    KUMAR PRAKASHAN|Exercise SECTION -D|3 Videos

  • WORK AND ENERGY

    KUMAR PRAKASHAN|Exercise QUESTION & ANSWER (ADDITIONAL NUMERICALS FOR PRACTICE)|50 Videos

Similar Questions

Explore conceptually related problems

Two identical springs are fixed at one end and masses 1kg and 4kg are suspended at their other ends. They are both strethced down form their mean position and let go simultaneously. If they are in the same phase after every 4 seconds then the springs constant k is

Statement-1 : The flash of lightening is seen before the sound of thunder is heard Statement-2 : The sound of thunder is produced after the flash of lightening.

When two tuning forks (fork 1 and fork 2 ) are sounded simultaneously, 4 beats per second are heard. Now, some tape is attached on the prong of the fork 2 . When the tuning forks are sounded again, 6 beats per second are heard. If the frequency of fork 1 is 200 Hz , then what was the original frequency of fork 2 ?

Assertion: If a body is dropped from the top of a twoer of height h and another body is thrown up simultaneously with velocity u from the foot of the tower, then both of them would meet after a time (h)/(u) . Reason: For a body projected upwards, the distance covered by the body in the last second of its upwards journey is always 4.9m irrespective of velocity of projection (g=9.8 m//s^(2))

The thunder sound is heard on the carth after 10 8 of the flash of lightning, then find the approximate distance of the thundering cloud from the earth. Take speed of sound 340 ms^(-1)

The sun is seen two minutes earlier than the actual sunrise and the sun is seen for two minutes more even after the actual sunset. Why?

At a time when it is cloudy. there may be frequent thunder and lightning. The sound of thunder takes some time to reach you after you see the lightning . Can you answer why this happens ?

An electric toaster uses nichrome for its heating element. When a negligibly small current passes through it, its resistance at room temperature (27.0^(@)C) is found to be 75.3 Omega . When the toaster is connected to a 230 V supply, the current settles, after a few seconds, to a steady value of 2.68 A. What is the steady temperature of the nichrome element ? The temperature coefficient of resistance of nichrome averaged over the temperature range involved , is 1.70 xx 10^(-4) ""^(@) C^(-1) .

A narrow sound pulse (for example, a short pip by a whistle) is sent across a medium (a) Does the pulse have a definite (i) frequency (ii) wavelength (iii) speed of propagation? (b) If the pulse rate is 1 after every 20s. (that is the whistle is blown for a split of second after every 20s), is the frequency of the note produced by the whistle equal to 1/20 or 0.05Hz?

KUMAR PRAKASHAN-SOUND-QUESTIONS AND ANSWERS (Answer the following questions is short:)
  1. The frequency of a source of sound is 100 Hz. How many times does it v...

    Text Solution

    |

  2. What is loudness of sound? On what factors does it depend?

    Text Solution

    |

  3. A boy heard a sound of frequency 100 Hz at a distance of 500 m from th...

    Text Solution

    |

  4. Flash and thunder are produced simultaneously. But thunder is heard a ...

    Text Solution

    |

  5. Two children are at opposite ends of an aluminium rod. One strikes the...

    Text Solution

    |

  6. Does the sound follow the same laws of reflection as light does? Expla...

    Text Solution

    |

  7. When a sound is reflected from a distant object, an echo is produced. ...

    Text Solution

    |

  8. Give two practical applications of reflection of sound waves.

    Text Solution

    |

  9. A man fires a rifle in front of a cliff and hears the echo after 3 sec...

    Text Solution

    |

  10. Why is echo not heard in a small room?

    Text Solution

    |

  11. A person has a hearing range from 20 Hz to 20 kHz. What are the typica...

    Text Solution

    |

  12. Explain how bats use ultrasound tt catch a prey.

    Text Solution

    |

  13. How is ultrasound used for cleaning?

    Text Solution

    |

  14. A sound wave travels at a speed of 339 ms^(-1) . If its wavelength is ...

    Text Solution

    |

  15. A sonar device on a submarine sends out a signal and receives an echo ...

    Text Solution

    |

  16. A ship which is stationary is at a distance of 2800 m from the seabed...

    Text Solution

    |

  17. Cracks in bones can be detected using ………

    Text Solution

    |

  18. Draw a neat and cleaned diagram of human ear and label the auditory pa...

    Text Solution

    |

  19. Draw graphical representation of the wave shaper for (1) low-pitched s...

    Text Solution

    |

  20. When the wire of a guitar is plucked, . What types of waves are produc...

    Text Solution

    |